FileInfo.AppendText-Methode
Erstellt einen StreamWriter, der der Datei Text hinzufügt, die von dieser Instanz von FileInfo dargestellt wird.
Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Function AppendText As StreamWriter
'Usage
Dim instance As FileInfo
Dim returnValue As StreamWriter
returnValue = instance.AppendText
public StreamWriter AppendText ()
public:
StreamWriter^ AppendText ()
public StreamWriter AppendText ()
public function AppendText () : StreamWriter
Rückgabewert
Ein neuer StreamWriter.
Hinweise
In der folgenden Tabelle sind Beispiele für andere typische oder verwandte E/A-Aufgaben aufgeführt.
Aufgabe |
Beispiel in diesem Thema |
|---|---|
Erstellen einer Textdatei. |
|
Schreiben in eine Textdatei. |
|
Lesen aus einer Textdatei. |
Beispiel
Im folgenden Beispiel wird Text an eine Datei angefügt, und die Datei wird gelesen.
Imports System
Imports System.IO
Public Class Test
Public Shared Sub Main()
Dim fi As FileInfo = New FileInfo("c:\temp\MyTest.txt")
Dim sw As StreamWriter
' This text is added only once to the file.
If fi.Exists = False Then
'Create a file to write to.
sw = fi.CreateText()
sw.WriteLine("Hello")
sw.WriteLine("And")
sw.WriteLine("Welcome")
sw.Flush()
sw.Close()
End If
' This text will always be added, making the file longer over time
' if it is not deleted.
sw = fi.AppendText()
sw.WriteLine("This")
sw.WriteLine("is Extra")
sw.WriteLine("Text")
sw.Flush()
sw.Close()
'Open the file to read from.
Dim sr As StreamReader = fi.OpenText()
Dim s As String
Do While sr.Peek() >= 0
s = sr.ReadLine()
Console.WriteLine(s)
Loop
sr.Close()
End Sub
End Class
using System;
using System.IO;
class Test
{
public static void Main()
{
FileInfo fi = new FileInfo(@"c:\temp\MyTest.txt");
// This text is added only once to the file.
if (!fi.Exists)
{
//Create a file to write to.
using (StreamWriter sw = fi.CreateText())
{
sw.WriteLine("Hello");
sw.WriteLine("And");
sw.WriteLine("Welcome");
}
}
// This text will always be added, making the file longer over time
// if it is not deleted.
using (StreamWriter sw = fi.AppendText())
{
sw.WriteLine("This");
sw.WriteLine("is Extra");
sw.WriteLine("Text");
}
//Open the file to read from.
using (StreamReader sr = fi.OpenText())
{
string s = "";
while ((s = sr.ReadLine()) != null)
{
Console.WriteLine(s);
}
}
}
}
using namespace System;
using namespace System::IO;
int main()
{
FileInfo^ fi = gcnew FileInfo( "c:\\temp\\MyTest.txt" );
// This text is added only once to the file.
if ( !fi->Exists )
{
//Create a file to write to.
StreamWriter^ sw = fi->CreateText();
try
{
sw->WriteLine( "Hello" );
sw->WriteLine( "And" );
sw->WriteLine( "Welcome" );
}
finally
{
if ( sw )
delete (IDisposable^)sw;
}
}
// This text will always be added, making the file longer over time
// if it is not deleted.
StreamWriter^ sw = fi->AppendText();
try
{
sw->WriteLine( "This" );
sw->WriteLine( "is Extra" );
sw->WriteLine( "Text" );
}
finally
{
if ( sw )
delete (IDisposable^)sw;
}
//Open the file to read from.
StreamReader^ sr = fi->OpenText();
try
{
String^ s = "";
while ( s = sr->ReadLine() )
{
Console::WriteLine( s );
}
}
finally
{
if ( sr )
delete (IDisposable^)sr;
}
}
import System.*;
import System.IO.*;
class Test
{
public static void main(String[] args)
{
FileInfo fi = new FileInfo("c:\\temp\\MyTest.txt");
// This text is added only once to the file.
if (!(fi.get_Exists())) {
//Create a file to write to.
StreamWriter sw = fi.CreateText();
try {
sw.WriteLine("Hello");
sw.WriteLine("And");
sw.WriteLine("Welcome");
}
finally {
sw.Dispose();
}
}
// This text will always be added, making the file longer over time
// if it is not deleted.
StreamWriter sw = fi.AppendText();
try {
sw.WriteLine("This");
sw.WriteLine("is Extra");
sw.WriteLine("Text");
}
finally {
sw.Dispose();
}
//Open the file to read from.
StreamReader sr = fi.OpenText();
try {
String s = "";
while ((s = sr.ReadLine()) != null) {
Console.WriteLine(s);
}
}
finally {
sr.Dispose();
}
} //main
} //Test
Das folgende Beispiel veranschaulicht das Anfügen von Text an das Ende einer Datei und das Ausgeben des Ergebnisses der Anfügeoperation in der Konsole. Die Datei wird beim ersten Aufruf dieser Routine erstellt, sofern sie nicht vorhanden ist. Anschließend wird der angegebene Text an die Datei angefügt.
Imports System
Imports System.IO
Public Class AppendTextTest
Public Shared Sub Main()
Dim fi As New FileInfo("temp.txt")
Dim sw As StreamWriter = fi.AppendText()
' Create a reference to a file, which might or might not exist.
' If it does not exist, it is not yet created.
' Create a writer, ready to add entries to the file.
sw.WriteLine("Add as many lines as you like...")
sw.WriteLine("Add another line to the output...")
sw.Flush()
sw.Close()
Dim sr As New StreamReader(fi.OpenRead())
' Get the information out of the file and display it.
' Remember that the file might have other lines if it already existed.
While sr.Peek() <> -1
Console.WriteLine(sr.ReadLine())
End While
End Sub 'Main
End Class 'AppendTextTest
using System;
using System.IO;
public class AppendTextTest
{
public static void Main()
{
// Create a reference to a file, which might or might not exist.
// If it does not exist, it is not yet created.
FileInfo fi = new FileInfo("temp.txt");
// Create a writer, ready to add entries to the file.
StreamWriter sw = fi.AppendText();
sw.WriteLine("Add as many lines as you like...");
sw.WriteLine("Add another line to the output...");
sw.Flush();
sw.Close();
// Get the information out of the file and display it.
// Remember that the file might have other lines if it already existed.
StreamReader sr = new StreamReader(fi.OpenRead());
while (sr.Peek() != -1)
Console.WriteLine( sr.ReadLine() );
}
}
using namespace System;
using namespace System::IO;
int main()
{
// Create a reference to a file, which might or might not exist.
// If it does not exist, it is not yet created.
FileInfo^ fi = gcnew FileInfo( "temp.txt" );
// Create a writer, ready to add entries to the file.
StreamWriter^ sw = fi->AppendText();
sw->WriteLine( "Add as many lines as you like..." );
sw->WriteLine( "Add another line to the output..." );
sw->Flush();
sw->Close();
// Get the information out of the file and display it.
// Remember that the file might have other lines if it already existed.
StreamReader^ sr = gcnew StreamReader( fi->OpenRead() );
while ( sr->Peek() != -1 )
Console::WriteLine( sr->ReadLine() );
}
import System;
import System.IO;
public class AppendTextTest {
public static function Main() : void {
// Create a reference to a file, which might or might not exist.
// If it does not exist, it is not yet created.
var fi : FileInfo = new FileInfo("temp.txt");
// Create a writer, ready to add entries to the file.
var sw : StreamWriter = fi.AppendText();
sw.WriteLine("Add as many lines as you like...");
sw.WriteLine("Add another line to the output...");
sw.Flush();
sw.Close();
// Get the information out of the file and display it.
// Remember that the file might have other lines if it already existed.
var sr : StreamReader = new StreamReader( fi.OpenRead() );
while (sr.Peek() != -1)
Console.WriteLine( sr.ReadLine() );
}
}
AppendTextTest.Main();
.NET Framework-Sicherheit
- FileIOPermission zum Lesen und Anfügen von Dateien. Zugeordnete Enumerationen: FileIOPermissionAccess.Read, FileIOPermissionAccess.Append
Plattformen
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile für Pocket PC, Windows Mobile für Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
.NET Compact Framework
Unterstützt in: 2.0, 1.0
Siehe auch
Referenz
FileInfo-Klasse
FileInfo-Member
System.IO-Namespace
StreamWriter
Weitere Ressourcen
Datei- und Stream-E/A
Gewusst wie: Lesen aus einer Textdatei
Gewusst wie: Schreiben von Text in eine Datei
Grundlegende Datei-E/A
Gewusst wie: Lesen und Schreiben einer neu erstellten Datendatei